Multiple-blade starting-switch.



No. 638,627. Patented Dec. 5, [899. G. S. DUNN.

MULTIPLE BLADE STARTING SWITCH.

(Application filed Apr. 29, 1899.)

4 SheetsShaet I.

(No Model.)

Invento 1, Cfano S. Dunn- Witnessesiwa WflaM (Application filed Apr. 29, 1899.)

4 Sheets-Sheet 2.

(N6 Modal.)

Invenkor,

Gal 10 S. Dunn bzr M -f, K

Witnesses: I W W zM Patented Dec. 5, 1899. G. S. DUNN.

MULTIPLE BLADE STARTING TGH.

(Application file A (No Model.)

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I D THE NORRIS PETERS CO PHOTULITHU WASNING No. 638,627. Patented Dec. 5, I899.

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MULTIPLE BLADE STARTING SWITCH.

(Application filed Apr. 29, 1899.)

4 Sheets-Sheet 4.

(No Model.)

Inventor,

Qano ,51 Dunn, b A Qin J AZ 0722.

UNITED STATES PATENT OFFICE.

GrANO S. DUNN, OF EAST ORANGE, NEW JERSEY, ASSIGNOR TO THE OROOKERJVHEELER COMPANY, OF NEW JERSEY.

MULTIPLE-BLADE STARTING-SWITCH.

SPECIFICATION forming part of Letters Patent NO. 638,627, dated. December 5, 1899. Application filed April 29,1899. Serial No. 715,040. \1 lo model.)

To all whom it may concern.-

Be it known that I, GANO S. DUNN, a citizen of the United States of America, and a resident of East Orange, Essex county, New Jersey, have invented certain new and useful Improvements in Multiple-Blade Starting- Switches, of which the following is a specification.

The principal feature of this invention is in the use, in connection with a rheostat, in an electrical circuit of a number of independent hand operated resistance controlling knife-switches which are closed to make contact with the series of resistances of the rheostat, together with an interlocking device for preventing the closure of the resistancecontrolling switches in other than the proper order to efiect a graded increase in the current. By the employment of independentlyoperated switches which must be successively grasped by the hand and closed a sufficient time is given to the motor to speed up and check the excess of current which would flow were resistance cut out too rapidly. It is thus possible to utilize in connection with a rheostat the best form of contact-mamely, a switch-blade and jaws. The contacts are of such a nature as not to be injured by the sparking attending the breaking of connection, and their number may be reduced to that required by the electrical conditions attending the starting of the motor.

The switches may be arranged either in multiple or series relation, and there may be in addition a circuit-closing switch which interlocks with the resistance controlling switches, so that it cannot be brought from open to closed position except when the resistance-controlling switches are open. The circuit-closing switch may be also an electromagnetic circuit-breaker. In this combination with an electromagnetic current-breaker the invention is an improvement on the electromagnetic circuit-breaker disclosed in my United States Patent No. 601,871, dated April 5, 1898. v p I In the accompanying four sheets of drawings, which form a part of this specification, Figure 1 is one form of the invention in which the switches are in multiple relation, the switches and interlocking device being mounted on a board and shown in perspective and the electrical connections shown diagrammatically. Fig. 2 shows a modified arrangement of resistances which may be used with either of the forms of switches herein described. Fig. 3 shows in similar manner to Fig. 1 another form of the invention in which an automatic circuit-breaker and a double-pole main switch are also mounted on the board and included in the circuit. Fig. 4 is a section on the line so no of Fig. 3, the side with the hinges of the switch-blades being removed, all of the resistance-sh unting switches being open, and the electromagnetic circuitbreaker and double-pole switch being closed. Fig. 5 is a similar section in which all of the switches are closed. Fig. 6 is a similar section in which the resistance-shuntin g switches are closed and the electromagneticcircuit breaker and double-pole switch are open. Fig. '7 is a section 011 the line y y of Fig. 3, showing the electromagnetic circuit-breaker. Fig.

8 shows in similar manner to Fig. 1 another form of the invention in which the resistancecontrolling switches are in series.

In the form shown in Fig. 1 a series of resistance-controlling switches 1 2 3 4: 5 are .mounted on a suitable base .13. These switches are connected on the hinge sides 6 to one of the leads L and on the jaw sides 7 to points along the sections 8, 9, 10, and 11 of the resistances. The-hinges are on a common base, so as to conveniently make the connection to the lead. hen the switch 1 is closed the circuit is from the first lead through all the sections of resistance to the field F and armature A of the motor to be regulated to the other lead. tVhen the switch 2 is closed, the circuit is around the sect-ion S, but through the other sections 9, 10, and 11. The closure of the switch 3 cuts out sections 8 and 9. The closure of switch a cuts out sections 8,9, and 10. of the sections and connects the lead to the motor without external resistance. The sections of resistance which are thus successively cut out vary in value logarithmatically, each bearing substantially the same ratio to the remaining resistance in the circuit, so that the surge of current on the successive closure or" the switches will be evenly divided between The closure of switch 5 cuts out all them. To efiect this, the switches must be closed in the definite order which has been indicated, and a locking-bar 12 is provided, which prevents the closure of the switches in any other order. The bar lies under the blades of the switches and has a movement transverse thereto. The bar has a series of notches 13, 14, 15, 16, and 17, which may be brought under the switch-blades and in which the blades lie when the switches are closed. One side of each of the notches is beveled, with the exception of the notch 17 for the switch 5, which is last closed. Except when the corresponding notch is under a switch-blade its closure is prevented by the bar. \Vhen the switches are all open, the bar is drawn by the spring 18 to the left of the position shown until the pin 19 contacts with one of the standards 20, by which the bar is guided. In this position none of the notches, with the excep tion of notch 13, lie under the blades of the switches, and consequently only the blade 1 of the first switch can be closed. In closing this switch the blade contacts with the inclined side of the notch in which it enters. This cams the bar a slight distance to the right and brings the inclined side of notch It under switch 2, so that it can next be closed and the bar cam med an additional step thereby. The closure of each switch, with the exception of the switch to be last closed, cams the bar an additional step and positionsit so as to permit the closure of the succeeding switch. The switches after they have all been opened can onlybe closed in the definite order determined by the position of the notches on the bar. They can be opened in any order. When the switches are all closed, the current flows only through the last switch and the other switches maybe opened without disturbing the connection of the motor to the leads. If this is done, the connection will be so left that the current may be cut off suddenly by opening only a single switch. In practice from four to seven switches may be employed, although five are shown.

The switches herein described are also applicable with resistances arranged in other ways-as, for example, in the manner shown in Fig. 2, in which switches are successively closed to resistances of decreasing value disposed in multiple instead of around resistances in series.

In the form shown in Figs. 3 to 7 the re sistance-controlling switches close to the series of resistances of the rheostat, as before; but there is in addition in series in the circuit a switch 21, which is locked against closure when any of the resistance-controlling switches are closed, and a double-pole switch S, which is not mechanically connected with the other switches, by which the connection to both leads can be made and broken. These switches are in series with each other and, respecting the circuit, in series with the resistance-controllin g switches, although the latter are in multiple relation to each other.

It follows, therefore, that no current can pass through the motor-armature unless both the switch 21, the double-pole switch S, and one of the resistance controlling switches are closed. The switch 21, as shown, is held closed by a differentially-wound magnet 22 and is an automatic circuit-breaker which is thrown open by the spring-pressed plunger 23 when the magnetism ceases in the magnet, as is the case whenever either the current exceeds a certain amount or the potential falls below a certain amount. The main circuit is from one of the leads, through one side of the double-pole switch, wire 24, a few turns on the differentially-wound magnet, wire 25, the jaw side of the circuit-breaker switch 21, through this switch, one or more of the resistance-controllingswitches, the armatureA of the motor, the other side of the doublepole switch to the other lead I]. A branch circuit from the main circuit after passing through the circuit breaker switch 21 is through the wire 26, a fine winding on the differentially-wound magnet of the circuitbreaker, wire 27, the field F of the motor, through the double-pole switch to the lead L. No current can pass through either winding of the circuit-breaker magnet unless the double-pole switch is closed. It must, therefore, be first closed. Then upon closing the circuitbreaker switch current will flow through the fine winding, the armature 28, attached to the switch-blade, will be attracted, the switch will be held closed, and current will then flow through the field of the motor. Closure of the resistance-controlling switches may now be made in proper order to admit current to the armature, as described in connection with Fig. 1. The current through the armature also passes through the few turns of the dif ferential magnet in a contrary direction to the current in the fine winding and counteracts the magnetizing effect of the fine winding, but not sufficiently to reduce the magnetism and release the switch-blade unless the How of current becomes excessive. Projecting from the locking-bar is a spring-controlled latch 29. This latch prevents the closure of the circuitbreaker switch it the bar has been displaced by the closure of any of the resistance-controlling switches, as shown in Fig. (3. If none of the resistance-controlling switches are closed and the bar is at its extreme position to the left, the circuitbreaker switch can be closed past the end of the latch, as shown in Fig. 1. If after the circuit-breaker switch is closed the resistance-controllingswitches are closed, the lock ing-bar will be cammed to the right and the latch will contact with the side of the blade of the circuit-breaker switch and be pushed back against its spring, as shown in Fig. 5. If while in this position the circuit-breaker opens from any cause, as from the cutting off of current by opening the double-pole switch, the latch will be thrown out underneath by its spring, as shown in Fig. 0, and.

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the circuit-breaker cannot again be closed until the resistance-controlling switches have been opened.

On the form shown in Fig. 8 the resistancecontrolling switches are placed in series insteadof in multiple; but they are manipulated in the sameway and their closure in other than a definite Way is prevented by the lockingbar, as before.

WVhat I claim, and desire to secure by Letters Patent of the United States, is-

1. A rheostat provided with a set of independently-operated switches, and means for preventing closure of contact at the switches, except in definite order, substantially as described.

2. A rheostat comprising a set of switches, a bar to prevent the closure of contact at the switches, and notches in the bar shaped and positioned to prevent closure of contact at the switches except in definite order substan tially as described.

3. A rheostat com prisinga set of switches, a bar to prevent closure of contact at the switches, notches in the bar shaped and positioned to prevent closure of contact at the switches except in definite order, an electromagnetic circuit-breaker, and a latch on the bar to prevent closure of contact at the electromagnetic circuit-breaker, except when all rheostat-contacts are open, substantially as described.

Signed bynie in New York city, New York, this 27th day of April, 1899.

GANO S. DUNN. \Vitnesses:

THOMAS EWING, J r., GEORGE H. GILMAN. 

